不要将包含的嵌入图像保存到附件中（如签名图像）

Question

我在 C# 中处理 VSTO。当我单击按钮时，我将附件保存在文件夹中。我的问题是：当我有一封带有签名图片的丰富电子邮件时，我的附件中有一个元素。但我不想保存该图像。 Outlook（应用程序）将此附件隐藏在附件区域中！那为什么不是我呢:-(

我的代码很简单：

MailItem MailItemSelected =  this.OutlookItem;   
foreach (Attachment a in MailItemSelected.Attachments)
{
   a.SaveAsFile(path + a.FileName);
}

但我没有找到不保存签名图像的测试。

Answer 1

2022 年 Outlook 365 的新答案

标志的答案对我不起作用，所以我开始调查调试器中发生了什么。

我发现微软明显改变了标志的规则，因为我在调试器中看到的值与旧标志解决方案中给出的值不匹配。

要让它今天在 Outlook 365 中工作，只需忽略标志不为 0 的附件：

    var flags = attachment.PropertyAccessor.GetProperty("http://schemas.microsoft.com/mapi/proptag/0x37140003");

    if (flags == 0)
    {
      //
      // Normal attachment, not embedded image etc, so save it
      //
    }

Answer 2

标志解决方法对我不起作用。我正在为 Outlook 2016 开发解决方案，并设法使用以下代码过滤附件：

foreach (Attachment attachment in mailItem.Attachments)
            {
                //exclude inline images
                if (!mailItem.HTMLBody.Contains(attachment.FileName))
                {
                    //the attachment is not an inline attachment, YOUR CODE HERE
                }
    }

如果标签中提到了每个附件，这基本上是检查 HTML 正文。

---

编辑：如果您在正文中键入附件的名称，前一种方法可能会跳过附件。这不太可能跳过误报

if (!mailItem.HTMLBody.Contains("cid:" + attachment.FileName))

Answer 3

我们需要在 Outlook 加载项中仅显示“邮件附件”（而不是用于呈现的嵌入式附件），这就是可行的方法。

 if (mailItem.Attachments.Count > 0)
        {
            // get attachments
            foreach (Attachment attachment in mailItem.Attachments)
            {
                var flags = attachment.PropertyAccessor.GetProperty("http://schemas.microsoft.com/mapi/proptag/0x37140003");

                //To ignore embedded attachments -
                if (flags != 4)
                {
                    // As per present understanding - If rtF mail attachment comes here - and the embeded image is treated as attachment then Type value is 6 and ignore it
                    if ((int)attachment.Type != 6)
                    {

                        MailAttachment mailAttachment = new MailAttachment { Name = attachment.FileName };
                        mail.Attachments.Add(mailAttachment);
                    }

                }

            }
        }

Answer 4

看到这个问题有一些 +2k 的点击率并且仍然没有得到回答，这是我对返回非内联附件列表的静态实用程序方法的尝试：

/// <summary>
/// Method to get all attachments that are NOT inline attachments (like images and stuff).
/// </summary>
/// <param name="mailItem">
/// The mail item.
/// </param>
/// <returns>
/// The <see cref="List"/>.
/// </returns>
public static List<Outlook.Attachment> GetMailAttachments(Outlook.MailItem mailItem) {
    const string PR_ATTACH_METHOD = "http://schemas.microsoft.com/mapi/proptag/0x37050003";
    const string PR_ATTACH_FLAGS = "http://schemas.microsoft.com/mapi/proptag/0x37140003";

    var attachments = new List<Outlook.Attachment>();

    // if this is a plain text email, every attachment is a non-inline attachment
    if (mailItem.BodyFormat == Outlook.OlBodyFormat.olFormatPlain && mailItem.Attachments.Count > 0) {
        attachments.AddRange(
            mailItem.Attachments.Cast<object>().Select(attachment => attachment as Outlook.Attachment));
        return attachments;
    }

    // if the body format is RTF ...
    if (mailItem.BodyFormat == Outlook.OlBodyFormat.olFormatRichText) {
        // add every attachment where the PR_ATTACH_METHOD property is NOT 6 (ATTACH_OLE)
        attachments.AddRange(
            mailItem.Attachments.Cast<object>().Select(attachment => attachment as Outlook.Attachment).Where(thisAttachment => (int)thisAttachment.PropertyAccessor.GetProperty(PR_ATTACH_METHOD) != 6));
    }

    // if the body format is HTML ...
    if (mailItem.BodyFormat == Outlook.OlBodyFormat.olFormatHTML) {
        // add every attachment where the ATT_MHTML_REF property is NOT 4 (ATT_MHTML_REF)
        attachments.AddRange(
            mailItem.Attachments.Cast<object>().Select(attachment => attachment as Outlook.Attachment).Where(thisAttachment => (int)thisAttachment.PropertyAccessor.GetProperty(PR_ATTACH_FLAGS) != 4));
    }

    return attachments;
}

Answer 5

我找到了解决方案的一部分。 当您创建电子邮件时，图像嵌入的大小为 0。因此您可以排除它。

但是当我阅读电子邮件时它是不对的。

MailItem MailItemSelected =  this.OutlookItem;   
foreach (Attachment a in MailItemSelected.Attachments)
{                                    
   if(a.Size != 0)
      a.SaveAsFile(path + a.FileName);
}

当我阅读电子邮件时，我找到了一个解决方案，但它不是很好。所以我写了它，但如果有人认为有更好的，我喜欢它。 在我的示例中，我尝试使用 PropertyAccessor 获取 Flag 属性，如果它是嵌入图像，那没关系，否则我会引发异常。

MailItem MailItemSelected =  this.OutlookItem;   
foreach (Attachment a in MailItemSelected.Attachments)
{
   bool addAttachment = false;
   try
   {
      string schemaPR_ATTACH_FLAGS = "http://schemas.microsoft.com/mapi/proptag/0x37140003"; 
      a.PropertyAccessor.GetProperty(schemaPR_ATTACH_FLAGS);
   }
   catch
   {
      addAttachment = true;
   }

   if (addAttachment && (a.Size != 0))
      a.SaveAsFile(path + a.FileName);
}